Custom Countersunk Magnets for Wind Turbine Blade Pitch Systems

Problem

A European wind turbine OEM needed countersunk NdFeB magnets for blade pitch position sensors on offshore installations. Their existing supplier delivered inconsistent coating quality — multiple batches failed salt spray testing after 200 hours, causing field failures in corrosive marine environments.

Solution

We sourced from a Ganzhou factory specializing in high-temperature grades with advanced coating lines. Key improvements:

• Switched from standard NiCuNi to epoxy over NiCuNi dual-layer coating
• Added 100% salt spray sampling (48hr accelerated test per batch)
• Implemented CMM dimensional verification on countersunk hole geometry

Specifications

• Material: NdFeB (N48SH)
• Shape: Disc with M4 countersunk hole
• Dimensions: Ø25 × 5 mm
• Tolerance: ±0.03 mm on OD, ±0.05 mm on countersunk depth
• Coating: NiCuNi + epoxy (dual layer)
• Operating temperature: -40°C to +150°C
• Volume: 5,000 pcs per quarter

Results

• Salt spray resistance exceeded 500 hours (vs. 200-hour failures before).
• Dimensional consistency within ±0.03 mm across full production run.
• Delivery cycle reduced from 8 weeks to 4 weeks using Ganzhou integrated supply chain.

Next Steps

Share your sensor housing drawings and environmental requirements to confirm grade and coating selection for your application.